38 
Trematodes of North Queensland 
The globular oral sucker is sub-terminal and has a diameter of 
0-24-0-26 mm. The ventral sucker is almost at the posterior end of 
the body. It is somewhat elongated and measures on an average 
0-50 X 0-47 mm. Both suckers are simple structures of the ordinary 
distomate type. 
The alimentary system is the most interesting feature of this parasite. 
From the mouth there proceeds backwards an extraordinarily long 
prepharynx. At first it lies towards the right side of the body, but 
when it has traversed about one-third of the body length it bends at 
right angles and passes across to the left side, where it again bends at 
right angles and passes forward along the left side. Midway on its 
course towards the anterior end of the body it turns abruptly backwards 
and passes down the mid line of the body to join the large pharyngeal 
bulb which is situated over the transverse part of the prepharynx. 
This configuration is fairly constant and is present in all the specimens. 
The pharyngeal bulb is extremely muscular and measures 0-28-0-35 
X 0-23-0-27 mm. The intestinal diverticula arise directly from the 
pharynx. They are short, widely dilated and somewhat in the form 
of a horseshoe. They terminate about two-fifths of the body length 
from the posterior end. 
The genital aperture is median and lies just behind the intestinal 
bifurcation. There is a stout, muscular cirrus-pouch, ovoid in shape, 
and measuring about 0-35 x 0-25 mm. It does not enclose the vesicula 
seminalis. The pars prostatica is of moderate size and almost globular. 
The ductus is rather wide. The vesicula seminalis, which opens into 
the pars prostatica without the intervention of any connecting duct, 
is of large size, being considerably larger than the cirrus-pouch. It is 
L-shaped, the lower limb being diverted outwards towards the right. 
The testes lie a little in front of the ventral sucker. They are not 
infrequently symmetrical, but are usually slightly oblique. They are 
placed together and usually overlap a httle. They are almost globular 
with an average diameter of 0-3 mm. 
Immediately in front of the testes and a little to the left lies a large 
globular receptaculum seminis, which is about the same size as the testes. 
In front of the receptaculum but more towards the mid line lies 
a smaller oval ovary. It is usually almost contiguous with the vesicula 
seminalis. The yolk glands are rather scattered and irregular; they 
are situated for the most part laterally over the intestinal diverticula. 
They do not extend beyond the latter posteriorly, but anteriorly they 
extend a little in front of the pharynx. The follicles are small. A 
